What is Causing the Current “Swarm” of Earthquakes in Alaska?

The most recent in a series of strange, repeated earthquakes occurring in Alaska struck shortly after 4 AM local time on Monday, just northeast of the village of Noatak. At present, seismologists remain uncertain as to what might be the cause of the ongoing tremors in the region.

The earthquake felt in the area on Monday had been a 5.7 quake, of equal magnitude to a “swarm” of tremblors that have occurred throughout the region since April, with reports of “mystery booms” reported even earlier, particularly during the winter months.

According to the Fairbanks, Alaskan Daily News Miner:

Before the swarm that began April 18, the last known quake of similar size in the area was a magnitude-5.5 quake that occurred in 1981, earthquake center seismologist Natasha Ruppert said.

The swarm of magnitude-5.7 quakes is connected to more than 300 smaller aftershocks, some with magnitudes in the high 3s, Ruppert said. The first quake and the others of that magnitude have been located in roughly the same area about 20 miles from Noatak. The community is 70 miles north of the Arctic Circle.

Monday’s quake was preceded by one minute by a magnitude-4.2 foreshock and followed by at least 10 aftershocks.

Scientists are working to understand the cause underlying the repeated quakes, which as reported earlier, have not occurred in the vicinity since 1981.